Patent GB-629106-A (GB)
Title: Improvements in the manufacture of intermediates for the production of dyes, in the manufacture of polymethin dyes and in photographic silver salt emulsions containing such dyes
IPC: C09B23/12
Filed: 1946-02-22
Abstract: A heterocyclic ternary nitrogen base having a dianiloisopropylidene group in the a - or g -position to the ternary nitrogen atom is prepared by condensing a compound of the formula Ar1-N=CH-OR1, wherein Ar1 is an unsubstituted or substituted phenyl group and R1 is an alkyl, substituted alkyl, or unsaturated aliphatic group, with a heterocyclic ternary nitrogen base having a methylene or aniloethylidene group attached to the carbon atom in the a - or g -position to the ternary nitrogen atom, by heating together in the presence of a water-binding agent, e.g. zinc chloride. Numerous methylene and aniloethylidene bases are specified.  3 - Ethyl - 2 - dianiloisopropylidenebenzthiazoline is prepared by heating together 3-ethyl-2-methylenebenzthiazoline or 3-ethyl-2-aniloethylidenebenzthiazoline, ethylisoformanilide, and zinc chloride. 5-Chloro-3-ethyl-2-aniloisopropylidenebenzthiazoline, 3 - ethyl - 2 - dianiloisopropylidene - 6 : 7 - benzbenzthiazoline, 3 - ethyl - 2 - dianiloisopropylidenebenzselenazoline, 4 -methyl - 3 - ethyl - 2 - dianiloisopropylidene - D 4 - thiazoline, 3 - methyl - 2 - dianiloisopropylidenethiazolidine, 3 - ethyl - 2 - aniloisopropylidenethiazolidine, 1 - ethyl - 4 - dianiloisopropylidene - 1 : 4 - dihydroquinoline, 1 - ethyl - 2- dianiloisopropylidene - 1 : 2 - dihydroquinoline, and 3 - ethyl - 2 - dianiloisopropylidenebenzoxazoline are similarly prepared.ALSO:Polymethine dyes are prepared by condensing a heterocyclic ternary nitrogen base having a dianiloisopropylidene group in the a - or g -position to the ternary nitrogen atom with a quaternary salt of a heterocyclic nitrogen compound having a methyl group in the a - or g -position to the quaternary nitrogen atom by heating together in presence of a condensing agent, the time and temperature of heating being sufficient to cause one molecular proportion of the base to combine with two molecular proportions of the quaternary salt to give a dye of probable general formula P1(R2)=C(CH=P2(R3)X)2, wherein P1(R2) and P2(R3) represent the residues of heterocyclic nitrogen compounds connected in the a - or g -position to the N atoms to which the groups R2 and R3 are attached, (R2 and R3 being alkyl, aralkyl, or aryl groups) and X represents an anion.  [Bis - 2 - (3 - ethylbenzthiazole)] [a  : b 1 - dimethine - 21 - (31 - ethylbenzthiazole)] - trimethinecyanine di-iodide is prepared by heating together 3 - ethyl - 2 - dianiloisopropylidenebenzthiazoline and 2-methylbenzthiazole ethiodide in pyridine.  Dyes may be similarly obtained in which the three nuclei are 2-(3-ethyl-6 : 7-benzbenzthiazole), 2 - (5 - chloro - 3 - ethylbenzthiazole), 2 - (3 - ethylbenzselenazole), 2 - (4 - methyl - 3-ethylthiazole), 2 - (3 - methyl - D 2 - thiazoline), 2 - (3 - ethyl - D 2 - thiazoline), 2 - (1 - ethylquinoline) and 4-(1-ethylquinoline).  Dyes may also be similarly obtained in which one nucleus is 4-(1-ethylquinoline) and the other two 2-(1-ethylquinoline) or 2-(3-ethyl-D 2-thiazoline), or one 2-(3-ethylbenzthiazole) and the other two 4 - (1 - ethylquinoline), 2 - (1 - ethylquinoline), 2 - (3 - ethylbenzoxazole), 2 - (3 - ethylbenzselenazole), or 5 - (3 - ethylrhodanine), or one 2 - (3 - ethylbenzselenazole) and the other two 2 - (1 - ethylquinoline), 2 - (3 - ethylbenzoxazole), 2 - (3 - ethylbenzthiazole), 2 - (3 - ethyl-6 : 7 - benzbenzthiazole), 2 - (1 : 3 : 3 - trimethylindolenine), 5 - (3 - ethylrhodanine), or 5 - (4 - keto - 2 - thio - 3 - ethyltetrahydro-oxazole), or one 2 - (4 - methyl - 3 - ethylthiazole) and the other two 2-(3-ethylbenzthiazole), 2 - (3 - ethylbenzselenazole), 5 - (3-ethylrhodanine), or 5 - (4 - keto - 2 - thio - 3-ethyltetrahydro-oxazole), or one 2-(3-ethyl-D 2-thiazoline) and the other two 2-(3-ethylbenzthiazole), 4 - (1 - ethylquinoline), or 5-(4 - keto - 2 - thio - 3 -ethyltetrahydrooxazole),-or one 2 - (5 - chloro - 3 - ethylbenzthiazole) and the other two 5-(3-ethylrhodanine), 5-1) - phenyl - 3 - ethyl - 2 - thiohydantoin), or 5 - (2 - diphenylamino - 4 - keto - D 2 - thiazoline) Specifications 408,272, [Group XX], 408,273, 561,172, 585,707, 629,122 and 629,123 are referred to.